1. Field of the Invention
The invention relates to a rotary shaft device applied in an electronic apparatus, in particular relates to a combination of a rotary shaft and a braking device which is capable of generating rotational and locating functions in an operating and fitting processes.
2. Description of the Related Art
Pivot shafts or rotary shafts, which are capable of being reciprocally freely rotated by an external force to be assembled on an electric apparatus (e.g., mobile phones, laptops, personal digital assistant, digital image capturing devices and electronic-books, etc.) to rotatably open and close covers, display screens or viewing windows thereof, are generally known as conventional skills.
Such pivot shaft or rotary shaft is generally assembled with components such as through-hole washers, friction plates and elastic members thereon, in which two ends of the rotary shaft are respectively fixed with fasteners, thereby preventing axial displacement of the above-described components and forming a rotary shaft structure with axial compactness. In conventional skills, a structure which is capable of being immediately formed with a locating function as a pivot shaft or a rotary shaft is rotated is disclosed.
One topic related to operations, motions and structure designs of the above-described cases shall be concerned is that, based on embedded structures such as locating flanges, convex pockets or concavo-convex locating portions which are disposed on relative planes of washers, elastic plates or elastic members, friction plates or related components, the flange is formed with locating function in the rotation operation of the rotary shaft when the flange is rotated to the position of the convex pocket. However, after an operation period, the locating effects of these flanges, convex pockets or concavo-convex locating portions applied on relative fitting planes of electronic products are soon inconsiderable due to abrasion constantly generated by rigid contacts.
As to the combination of the multiple washers and friction plates, together with in cooperation with energy storage and release of elastic rings or springs to attain rotational and locating functions of the rotary shaft or pivot shaft component applied in conventional skills, it will be understood by those who skilled in these arts in that the whole structure design and assembly fitting become more complicated, and an assembled arrangement length of the whole structure in an axial direction is greatly increased, thus to limitedly impair the arrangement space of the rotary shaft and the electronic apparatus.
Another topic related to assembly and fitting of the rotary shaft and the locating components is that the elastic clamping function or the force regulation of frictional resistance is acquired by operation of the lock-packing degree of the screw nut. If the packed washer is too slack, the rotary shaft (or a cover, a display screen) cannot have an ideal locating effect. However, if the packed washer is too tight, the washer is regularly formed with stress and deformation, and in particular abrasions are easily generated between the fitted components to cause unstableness and slackness of the rotary shaft after the rotary shaft is operated.
Therefore, it relatively becomes more inconvenient and difficult to adjust the screw nut to pack the washer by an assembling fitter for obtaining an ideal elastic clamping function or frictional resistance. In practice, the washer is often deformedly destroyed to form the rotary shaft as a defect product and to increase the manufacturing cost, and certainly these conditions are not our expectations.
Representatively speaking, these reference data reveal the conditions of usage and structural design of the rotary shaft, the locating components or components connected therewith. If the structure and the above-described applications of the rotary shaft and components connected therewith can be properly redesigned and reconsidered, the use patterns and the application conditions of the rotary shaft can be advancedly altered and therefore distinguished from conventional methods, and it is actually not only to improve conditions such as easy-to-produce stress and deformation destructions or abrasion on the fitted components, but also to increase the assembling convenience. For example, based on the structure design of the rotary shaft capable of satisfying without increasing fitting difficulty, providing a mechanism to prevent axial displacement or slackness, or featuring with aspects different from conventional skills, conditions such as easy-to-produce abrasion and imperfect locating effect in the operation process of the rotary shaft in conventional skills can be improved. However, these topics are not taught or disclosed in the above-mentioned reference data.